1. Technical Field
The present invention relates to a vertical split type (barrel) compressor, and in particular, to cooling of a seal structure thereof.
2. Description of the Related Art
The compressor casing (hereinafter referred to as “casing”) of a vertical split type compressor generally includes components, such as rotors, blades, and so forth, in the interior thereof. In the casing, which accommodates the components therein, end lids, which are called heads, are provided at both ends in the axial direction. The heads are provided so as to confine the components from both ends in the axial direction of the casing. O-rings that prevent leakage of compression fluid are provided between the outer circumferential surfaces of the heads and the inner circumferential surface of the casing (see, for example, Japanese Examined Patent Application, Publication No. SHO-58-6079).
As a seal structure using O-rings, JP 58-6079 discloses a structure in which a recessed part is formed on the outer circumferential surface of a head, and a ring-shaped thin O-ring-retaining ring is provided in this recessed part. In this structure, the O-ring is provided by configuring an O-ring groove on the outer circumference of the O-ring-retaining ring. In addition, in this structure, an O-ring groove is also provided on the end surface of the O-ring-retaining ring (the surface orthogonal to the axial direction of the compressor), thereby providing an O-ring for sealing a gap formed with respect to the side surface of the recessed part that is provided on the outer circumferential surface of the head (the surface orthogonal to the axial direction of the compressor).